Sample cylinder, especially a sample cylinder that is provided with a filtration device for recovering cell material from body fluids

ABSTRACT

For the purpose of obtaining medical preparations by means of a printing technique, a specimen cylinder is provided with a syringe cone segment that can be separated from a cylinder segment. After the syringe cone segment has been removed, a filtering device with a filter which is held so as to be sealed relative to the inner wall of the specimen cylinder projects beyond its holder and beyond the cylinder segment in an operational position of the filtering device and can be pressed onto a specimen carrier in a simple manner.

PRIORITY CLAIM

This is a U.S. national stage of application No. PCT/DE01/01839, filedon 16May 2001. Priority is claimed on that application and on thefollowing application: Country: Germany, Application No.: 100 24 137.9,Filed: 18 May 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is directed to a sample cylinder or specimen cylinder witha syringe cone segment, particularly with a filtering device forrecovering cell material from body fluids.

2. Description of the Related Art

A filtering device for separating and collecting cells and particlesfrom liquids is known from DE 3719302, which corresponds to U.S. Pat.No. 4,973,450. Efficiency can be increased through the use of thisdevice, particularly in quantitative evaluation methods, e.g., in urinesediment analysis. The device described in the above-cited reference hasa specimen cylinder with a syringe cone segment. A filtration tube whichis displaceable in the manner of a syringe plunger and has a one-stageor two-stage filter device at one end is inserted into the specimenvessel.

Diagnostic chores, e.g., in the field of urine analysis, require thatthe particles occurring in urine, such as erythrocytes, leukocytes,urothelial cells, other accompanying cells, crystalline bodies, hyalinecylinders and germs are concentrated and accumulated from a largequantity of liquid, e.g., from a full bladder or from 50-ml or 100-mlsamples, without losses in a sediment or in a constant 1-ml amount ofliquid. This allows the filtering device to separate and collect cellsand particles from liquids, e.g., from urine. Qualitative evaluation iscarried out in a manner known per se by adding the specimen by drops tocell counters.

In connection with improved diagnostic possibilities, the known devicewas improved for cytological purposes where the cell material onmicroscope slides should have a perfect morphology. To this end, afiltration tube in a known device is guided inside a specimen cylinderwith a syringe cone segment and adjoining cylinder segment so as to besealed against the cylindrical inner wall of the specimen cylinder. Whena liquid is drawn in the manner of a syringe and received in thespecimen cylinder, and the syringe cone is closed or the specimencylinder, with the filtration tube removed, is filled with body fluidand then the filtration tube is inserted, the specimen liquid passesthrough the filtering device when the filtration tube is pressed downagainst the specimen liquid and collects in the filtration tube orpasses out in some other manner.

During the filtration process, additional particles collect on a filtersurface which projects particularly over the filtering device. Thefiltration tube is then usually removed from the specimen cylinder afterthe specimen liquid has been withdrawn. The particles which havecollected on the filter surface can then be transferred to a slide,e.g., for microscopic diagnosis, so that an accumulated suspension inthe specimen cylinder which is needed for quantitative analysis isdispensed with.

This print technique has proven extremely successful for obtainingmedical preparations. However, in order to transfer the cell materialthat has collected on the filter surface to slides by this kind ofprinting, the filtration tube must be removed from the specimencylinder. For this purpose, after the filtrate or residue has beenremoved, the device which is now open is turned over and set on acellulose base, for example. The specimen cylinder can then be pulledout of the filtration tube against considerable resistance through theuse of corresponding force. In so doing, remainders of the specimen willinevitably flow down the outer wall and can wet the user's fingers aswell as the base. This risk of contamination, for example, in case ofinfectious material, is disadvantageous and is not tolerable for reasonsof hygiene.

Precisely in view of such a risk of contamination, reuse of devices thathave already been used should also be ruled out.

SUMMARY OF TILE INVENTION

This set of technical problems is solved generally in a specimencylinder with a syringe cone segment by the specimen cylinder accordingto the invention, wherein the syringe cone segment can be separated froma cylinder segment. In particular, the idea consists in that in aspecimen cylinder having a filtering device with a filter which is heldso as to be sealed relative to the inner wall of the specimen cylinder,a surface of the filter projects axially over its holder and over thecylinder segment in an operational position of the filtering device whenthe syringe cone segment is removed.

The steps undertaken in the specimen cylinder according to the inventionachieve a number of advantages. When the filtering device is insertedinto the specimen cylinder in the manner of a filtering tube, it nolonger needs to be removed from the specimen cylinder. Rather, thefilter surface with the collected cell contents and particles is freelyaccessible after the syringe cone segment is removed, for example, fortransferring these cell contents and particles onto a microscope slideor specimen carrier. For this purpose, the surface advisably projectsaxially over the holder of the filter as well as over the cylindersegment in this operational position and is accordingly freelyaccessible.

Consequently, the cell material that has collected on the surface of thefilter comes into contact with the environment when and only when italso undergoes further preparation. In particular, an unintentionaldrying out of the filter outside of the specimen cylinder is alsoimpossible. Rather, the filter surface with the cell material remains inthe microclimate of the specimen cylinder until the above-mentionedpreparation step. Also, a mechanical influence on the cell contents onthe filter surface, e.g., due to tilting of the filtering device duringremoval, striking against the free edge of the specimen cylinder or thelike, is reliably prevented by the steps according to the invention.

In a preferred construction, the cylinder segment and a portion of thesyringe cone segment form a common cylindrical inner wall of thespecimen cylinder. The syringe cone is accordingly completely severedfrom the cylinder segment, i.e., separation is effected in an areahaving a constant, cylindrical cross section and not in the area of thesyringe cone tapering toward the free end. As a result of this step, themaximum cross section of the specimen cylinder is available at theseparation point after the syringe cone segment is severed. Further, theaxial movability of the inserted filtering device can not be impaired inany way by this step. Moreover, the tightness of the holder relative tothe inner wall of the specimen cylinder is ensured, even up to theseparating point, because there is no change in cross section in theinner wall.

In a first alternative design, the cylinder segment and syringe conesegment are constructed in two pieces. Suitable steps must then be takento connect the syringe cone segment to the cylinder segment so as to betight against liquid.

When an axially stationary filtering device is desired, the holder ofthe filter can connect the cylinder segment and syringe cone segment toone another. A connection of this kind can be provided in a manner knownper se by suitable snap-in connections, catch connections and screwconnections. Sealing rings which guarantee a liquid-tight connection canbe provided in addition.

However, since axial movability of the filtering device is usuallynecessary for the tasks mentioned in the beginning, the cylinder segmentand syringe cone segment are advisably connected to one another by anouter and/or inner sleeve. With respect to an outer sleeve, the cylindersegment and syringe cone segment advisably have the same outer andpreferably the same inner diameter at least in the area of theseparation point. For an inner sleeve, identical inner diameters arealso usually required. When the inner sleeve extends over the entirecylindrical area of the specimen cylinder, there is also no problem withsealing relative to the holder for the filter. Alternatively, a frontside of an inner sleeve of this type can form a deliberate axial stopfor the filtering device, e.g., for fixing an exact volume of thesyringe cone segment.

Also, different inner diameters of the cylinder segment and syringe conesegment can be compensated by an inner sleeve with a stepped orgraduated outer diameter and an inner diameter can be made availablespecifically for filtering devices that are adapted for special tasks.

It is possible to construct the sleeves separately. Alternatively, asleeve of this type can also be constructed integral with the cylindersegment and/or with the syringe cone segment such that the cylindersegment and syringe cone segment are connected so as to overlap axially.In individual cases, a telescoping insertion of the cylinder segment andsyringe cone segment may also be adequate as a connection.

Besides the two-piece constructional variant, the cylinder segment andsyringe cone segment can also be constructed in one piece and can beseparable at a predetermined breaking point. In this variant also,separation is possible in a well-defined manner by means of thepredetermined breaking point. A predetermined breaking point of thiskind is usually formed at this location by a narrowing of the crosssection and, if required, can be mechanically reinforced by ribs whichbreak or tear in a suitable manner.

Regardless of whether a one-piece or two-piece construction is carriedout, it is provided in a further development that the connection of thesyringe cone segment to the cylinder segment is carried out in themanner of a safety lock or tamperproof closure such as is known in theart, e.g., for bottles. This step makes it possible to detect usedequipment in a reliable manner regardless of whether or not the specimencylinder according to the invention can regularly be separated intocylinder segment and syringe cone segment and then assembled again.

In exceptional cases, particularly for applications requiring highlysterile conditions, the latter feature is usually undesirable. In thatcase, it is provided that when the connection elements and/or sealingelements or the syringe cone segment itself are destroyed when thesyringe cone segment is severed from the cylinder segment, they can notbe put together again so as to be operational.

It can be provided particularly in the two-piece construction of thespecimen cylinder according to the invention that the specimen cylinderhas an axial stop for the filtering device in the area of the separationpoint of the syringe cone segment and cylinder segment. In particular,the severed edges of the syringe cone segment and cylinder segment canhave, as a stop, a projection which faces inward and projects over theinner wall. This step also ensures that a defined, predeterminablevolume is available on the syringe cone side.

The invention will be described more fully with reference to thedrawings which show embodiment examples only.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a specimen cylinder with insertedfiltering device according to the invention;

FIG. 2 shows the specimen cylinder according to FIG. 1 without thesyringe cone segment;

FIG. 3 shows a second embodiment example in section in the area of theseparation point;

FIG. 4 shows a third embodiment example;

FIG. 5 shows a fourth embodiment example; and

FIG. 6 shows a fifth embodiment example.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 1 shows a specimen cylinder 1, according to the invention,comprising a cylinder segment 2 and a separable syringe cone segment 3which are constructed in two pieces in the embodiment example shown inFIGS. 1 and 2. The syringe cone segment 3 which is closed by a cap 4 isconnected to the cylinder segment 2 by a holder 5 of a filtering device6, shown in a simplified manner, which is inserted into the specimencylinder 1 and which is also already known, e.g., from DE 3719302. Theholder 5 holds a filter 8 by a portion 11 so as to be sealed relative tothe inner wall 7 of the specimen cylinder 1. The filter 8 projectsaxially over the holder 5 by a surface 9. This projecting portion has amushroom-like appearance owing to a radial necking down of the filter 8due to the holder 5, e.g., due to a conical filter receptacle and acircumferential projection which faces radially inward.

The cylinder segment 2 and a portion 10 of the syringe cone segment 3together form the cylindrical inner wall 7 of the specimen cylinder 1.Consequently, the holder 5 can join the cylinder segment 2 and thesyringe cone segment 3 together by portion 11 which has a constant crosssection formed by the dimensioning of the inner cylindrical area of thespecimen cylinder 1.

Depending on the construction, this connection can be carried out bymeans of a simple press fit and/or clamping fit of the cylinder segment2 and syringe cone segment 3 on portion 11 of the holder 5. Catchclosures, snap-in closures or screw closures, not shown in particular,are all equally possible without difficulty. Further, sealing elementssuch as sealing rings 14 can be inserted in portion 11 in addition.These steps are essentially determined by the intended use of thespecimen cylinder 1 according to the invention.

In the embodiment form shown in FIGS. 1 and 2, the filtering device 6 isnot inherently axially displaceable in the specimen cylinder 1.Nevertheless, a liquid specimen can easily be sucked in by drawing outthe tube 15. Alternatively, for example, a suction pump, a balloon 17 ofsufficient size, or the like, can be fitted to the free end 13 of thespecimen cylinder 1. As a result of the liquid flowing through thefilter 8 in the direction indicated by the arrow 12, cell material thatis filtered out is deposited on the surface 9 of the filter 8.

After the collected liquid has been removed, possibly after removing thecap 4, including the liquid collected in the syringe cone segment 3, thesyringe cone segment 3 can be severed from the cylinder segment 2,according to the invention, in the plane 17 indicated by a dash-dot linein FIG. 1. In the operational position of the filtering device 6according to FIG. 2, the surface 9 then projects freely axially over thecylinder segment 2 and the holder 5.

In this embodiment example, the cylinder segment 2 and the holder 5 ofthe filtering device 6 can be nondetachably connected and, if necessary,can even be constructed so as to form one piece.

In order to place a medical preparation on a microscope slide orspecimen carrier 16, the cylinder segment 2 with the filtering device 6is carefully placed by its surface 9 on the specimen carrier verticallyas indicated by arrow 18 in FIG. 2 in order to transfer the cellmaterial located on the surface 9 to the specimen carrier 16.

When a cylindrical portion 25 of the syringe cone segment 24 and thecylinder segment 23 have the same inner cross section as is shown inFIG. 3, a common inner wall 26 of the specimen cylinder 20 is formed.Accordingly, the filtering device 27 can move freely axially. A tube 30which is guided within the specimen cylinder 20 and sealed relative tothe latter forms a holder 28 of the filter 29 at the same time. Then aspecimen liquid which is drawn in when the cap 33 is attached collectsin the tube 30.

When a filtering process is concluded, the filtrate located in the tube30 can be poured off, according to the prior art, the tube 30 can beremoved from the specimen cylinder 20 in the manner described above, andthe cell material located on the filter surface 31 can be transferred toa specimen carrier. Filtrate still remaining in the tube can serve as abackwash medium if required.

However, in the specimen cylinder according to the invention, the tube30 is restored to the position shown in FIG. 3 after the filtrate hasbeen poured off, and the filter surface 24 projects axially over theholder 28 of the filter 29 and over the cylinder segment 23 after thesyringe cone segment 24 has been removed for transferring the filteredout cell material to a specimen carrier.

For this purpose, in the two-piece embodiment form of the specimencylinder 20 according to FIG. 3, an outer sleeve 21 overlaps aseparation 22, shown in an enlarged view, between the cylinder segment23 and the syringe cone segment 24.

In a simple embodiment form, the outer sleeve 21 which is constructed asa shrink tubing, for example, can connect the cylinder segment 23 to thesyringe cone segment 24. However, solidly constructed sleeves 21 whichare formed in such a way that the syringe cone segment 24 and thecylinder segment 23 are connected with the sleeve 21 by means of a catchconnection, a snap connection or screw connection, possibly includingsuitable sealing elements, are preferable.

Further, separately constructed sealing rings 32 are additionallyprovided so that the holder 28 for the filter 29 of the filtering device27 is well-sealed relative to the inner wall 26.

In the specimen cylinder 35 according to FIG. 4, which is also atwo-part construction, the syringe cone segment 36 is constructed in themanner of a cap so as to axially overlap and engage over the cylindersegment 37. It can be ensured by means of suitable graduation (see arrow38) that a portion of the cylinder segment 36 and the cylinder segment37 form a common cylindrical inner wall 39. Due to this step, thefiltering device 40 is again freely movable axially within the specimencylinder 35.

Arrow 41 indicates the connection elements and/or sealing elements whichensure the liquid-tight connection of the syringe cone segment 36 to thecylinder segment 37. For example, these elements can be inserted sealingrings, suitably constructed projections and recesses which catch or snaptogether, a thread, or the like.

When it must be ensured in particular that the specimen cylinderaccording to the invention can not be reused, these connection elementsand/or sealing elements 41 are advisably destroyed when the syringe conesegment 36 is detached from the cylinder segment 37 in such a way thatit is no longer possible to reassemble them so as to be operational.

Accordingly, a connection between the syringe cone segment 36 and thecylinder segment 37 is constructed in the manner of a tamperproofclosure which allows reliable detection of tampering.

In addition to the two-piece construction of the specimen cylinderaccording to the invention, it is also possible to construct a specimencylinder 45 in one piece in a simple manner with respect tomanufacturing technique. The cylinder segment 46 and syringe conesegment 47 can then be separated in a regular manner at a predeterminedbreaking point 48 with a clearly defined area of separation. Apredetermined breaking point 48 of this kind usually has a cross sectionwhich is small enough to enable the cylinder segment 45 and syringe conesegment 47 to be separated easily by tearing or breaking thepredetermined breaking point 48. In order to ensure sufficientmechanical stability, reinforcing ribs 49, which are also provided withpredetermined breaking points themselves if need be, can furtherstrengthen the mechanically weak connection along the predeterminedbreaking point 48.

In a one-part construction of this kind, the specimen cylinder 45 canalso be designed so as to be reusable. Alternatively, it is alsopossible in this case to exclude reuse by appropriate tearing orbreaking of the predetermined breaking point 48 and/or ribs 49. In everycase, in a one-piece construction of the specimen cylinder 45 of thistype, it can easily be seen whether or not it has already been used.

FIG. 6 shows another two-part construction of a specimen cylinder 50with a cylinder segment 51 and a syringe cone segment 52. In thetwo-part embodiment form shown in FIG. 6, it is possible to provide theends of the cylinder segment 51 and syringe cone segment 52 that faceone another with a projection 53 which faces radially inward.

When projections of the type mentioned above are provided at the syringecone segment 52 as well as at the cylinder segment 51, they can also beused as a connection element and/or sealing element. In particular, aprojection 53 of this kind which projects inward also forms an axialstop for the filtering device 54. Accordingly, an exactly defined volumecan be predetermined inside the syringe cone segment 52 in theoperational position of the filtering device 54 according to FIG. 6.When the wall of the cylindrical portion of the syringe cone segment 52is constructed with a suitable thickness, its front side can also formthe stop for the filtering device 54 without the need for a projection53 projecting over the inner wall.

Further, FIG. 6 shows a radially circumferential, axially projecting lip55 at the end of the cylinder segment 50 facing the syringe cone segment52. This lip 55 is held in a sealing manner in a corresponding recess ofthe syringe cone segment 52. In this case, also, the abovementionedsteps for additional sealing and for a secure hold can again be providedin the form of sealing elements, snap-in and catch connections, threads,etc.

1. A specimen cylinder comprising: a cylinder segment having acircumferential inner wall; a syringe cone segment integrally formedwith the cylinder segment so that the cylinder segment and the syringecone segment form a one-piece element having a frangible structureforming a predetermined breaking point, wherein the one-piece elementcan be severed at the predetermined breaking point to separate saidsyringe cone segment from said cylinder segment, said syringe conesegment having an inner wall; and a filtering device held in saidcylinder segment and sealed relative to said inner wall of said cylindersegment, said filtering device comprising a filter and a holder whichholds the filter so that an axial end surface of the filter is coveredby said syringe cone segment when said syringe cone segment is connectedto said cylinder segment and said axial end surface projects axiallybeyond said holder and beyond said cylinder segment after said syringecone segment is separated from said cylinder segment.
 2. The specimencylinder of claim 1, wherein before said syringe cone segment isseparated from said cylinder segment, said inner wall of said cylindersegment and said inner wall of said syringe cone segment form a commoncylindrical inner wall of said specimen cylinder.
 3. The specimencylinder of claim 1, wherein said cylinder segment and said syringe conesegment can be separated without damaging the specimen cylinder.
 4. Thespecimen cylinder of claim 1, further comprising a tamperproof closurewhere said cylinder segment and said syringe cone segment can beseparated.
 5. The specimen cylinder of claim 1, further comprising meansfor rendering the specimen cylinder inoperable when said syringe conesegment is separated from said cylinder segment.
 6. The specimencylinder of claim 1, wherein said cylinder segment comprises an axialstop for positioning said filtering device.
 7. The specimen cylinder ofclaim 1, wherein the axial end surface of the filter is shaped so as tobe suitable for being pressed onto a specimen slide.
 8. A specimencylinder comprising: a cylinder segment having an inner wall; a syringecone segment integrally formed with the cylinder segment so that thecylinder segment and the syringe cone segment form a one-piece elementhaving a frangible structure forming a predetermined breaking point,wherein the one-piece element can be severed at the predeterminedbreaking point to separate said syringe cone segment from said cylindersegment; and a filtering device held in the cylinder segment andcomprising a filter and a holder, the holder having an outer radialsurface which sealingly engages the inner wall of the cylinder segmentand an inner radial surface which holds the filter, the filter having anaxial end surface which is covered by the syringe cone segment when thesyringe cone segment is connected to the cylinder segment and which,after the syringe cone segment is separated from the cylinder segment,projects axially beyond the holder and beyond the cylinder segment. 9.The specimen cylinder of claim 1, wherein said cylinder segment has aproximate end and a distal end, said predetermined breaking point beingarranged at said distal end, said axial end surface of said filterprojecting outward from said distal end after said syringe cone segmentis separated from said cylinder segment.
 10. The specimen cylinder ofclaim 8, wherein said cylinder segment has a proximate end and a distalend, said predetermined breaking point being arranged at said distalend, said axial end surface of said filter projecting outward from saiddistal end after said syringe cone segment is separated from saidcylinder segment.
 11. The specimen cylinder of claim 1, wherein saidfiltering device is arranged so that a filtrate can be drawn throughsaid filter into a space defined by said inner wall of said cylindersegment and said filtering device.